Silver Geo
 
Lake Shore Traps
Copper Harbor Conglomerate
Portage Lake Volcanics
Henry Cornwall Bedrock Geology of Delaware Quadrangle, Michigan USGS GQ 51

Neil Harri

Age of Lake Shore Traps:

Paces & Miller, 1993


Paleomagnetism of Silver Island Lavas:

    Diehl et al., 2009

    Kulakov et al., 2013

Swanson-Hysell et al, 2014, Geology 42: 475-478.